/Engine/Source/Runtime/Engine/Classes/GameFramework/Actor.h
Get axis-aligned cylinder around this actor, used for simple collision checks (ie Pawns reaching a destination). IfIsRootComponentCollisionRegistered()returns true, just returns its bounding cylinder, otherwise falls back to GetComponentsBoundingCylinder.
virtual void GetSimpleCollisionCylinder ( float & CollisionRadius, float & CollisionHalfHeight ) const